Core barrel operated float valve



June 13, 1939. Mv L. HACKER GORE BARREL OPERATED FLOAT VALVE Filed May 27, 1957 Patented June 13, 1939 UNITED STATES PATENT OFFICE 7 2,162,578 CORE BARREL OPERATED FLOAT VALVE Marcus L. Hacker, Houston, Tex.

6 Claims.

The invention relates to a float valve of. a particular type which is to be inserted in a string of pipe lowered into a well bore and is peculiar in that it is arranged to open to permit the passage of a core barrel or other tool through the string oi pipe and to thereafter be closed upon removal or the tool or piece of equipment from the pipe.

In the drilling of wellsit is not uncommon to encounter enormous pressures in the drilling and producing operation, so that it is desirable to havea back pressure valve in the string of pipe in the well bore which will cut oiT the flow oi! fluid upwardly through the string of pipe. Valves of the general back pressure type are well known. In present day drilling practices where core barrels, fishing tools, surveying tools or other instruments are lowered directly through the drill pipe or other string of pipe while it remains in the well bore and after the function of the tool is performed the tool is removed. It has been impossible to provide the string of pipe with the usual back pressure or float valve because with valves oi this general type it is impossible to permit the passage of a tool or other equipment therethrough.

It is one of. the objects of the present invention to provide a float or back pressure valve which will permit the-passage of a core barrel or other instrument thereto.

Another object of the invention is to provide a flap valve for pipe which will be held in open position by'a movable sleeve.

Another object of the invention is to provide-a float valve which can be held in open position by the passage of a tool therethrough.

Still another object or the invention is to provide the combination of a back pressure valve and a sleeve to hold the valve in open position,

which sleeve is in turn moved to operative or inoperative position by the passage of an instrument or tool therethrough.

Still another obiect of thehinvention is to provide a latching sleeve which is used to hold a back pressure valve in open position and which sleeve may be latched or unlatched as desired by an instrument moving therethrough.

Other and further objects or the invention wi be readily apparent when the following description is considered in connection with the accompanying drawing wherein:

Fig. 1 is a vertical sectional view of a drill stem assembly which has been equipped with the present core barrel operated float valve and showing the valve in closed position.

Fig. 2 is a section similar to Fig. 1 but showing v the valve held in open position.

Fig. 3 is a vertical sectional view showing the valve in closed position and illustrating the curved configuration oi the valve so that it will Application May 27, 1937, Serial No. 14 L988 :iccupy a minimum space when it is in open posi- Fig. 4 is a section taken on the line 4-4 'of Fig. 2 and looking upwardly to illustrate the curved configuration of the valve andthe position of the sleeve.

Fig. 5 is a side elevation of an assembly view showing one application of the valve for use in combination with a core barrel.

In Fig. l a section 01 pipe is illustrated at 2 and this may be the upper end of'any suitable piece of pipe which constitutes part of a string of pipe in a well bore and to which the invention is to be applied. For purposes of illustration this will be the upper end of a drill collar. The box member 3 of this pipe is arranged to receive the pin member 4 of the sub 5 so that the sub and the pipe are firmly aiiixed together. This sub 5 is of peculiar configuration in that it is cut away to form a chamber 6 and is provided with a shoulder I. The upper end of the sub carries the box member 8 which in turn receives the pin member 9 of a second or upper sub I, This sub in turn carries the box member II to receive the pin member H of the next adjacent section of pipe. The sub i is of. special construction in that it is provided with the usual central opening It, which is slightly enlarged at I! in order to receive the sleeve it. This sleeve is slidable in the opening it and is arranged to abut against the shoulder II in order to limit the upward movement thereof. The sleeve carries a plurality of spring arms 20, each or whichis provided with a lateral finger 2i which projects through an opening 22 in the sleeve and is arranged to be engaged in a recess 23 in e inside periphery of the passageii in the sub It. A plurality of these arms is provided and, as seen in Fig. 1. they serve to latch the sleeve in the position shown.

when a core barrel or other tool passes downwardly through the sleeve, such instrument will engage the curved portion 25 of. the springs and cause them to engage the shoulder portion 26 of the opening 22 so. that when the curved portion 25 is flattened out the finger 2| will be withdrawn from the recess 23. Naturally these springs exert a frictional engagement with the tool or instrument passing therethroughso that as soon as the latches are'released the sleeve will tend to move along with theinstrument. In Fig- 2 the sleeve is shown as having been moved downwardly .until the lower end 20 thereof engages the shoulder I. This limits further downward movement of the sleeve and the core barrel or other instrument will then continue its downward movement, sliding along the springs 20. In Fig. a core barrel 32 has been shown as the tool or instrument which eiieoted the movement of this sleeve.

A shoulder enlargement 33 is present on some c'ore barrels which is arranged to engage the abutment 34 in the pipe 2. An enlargement of this sort will, of course, actuate the springs and move the sleeve to the position shown in Fig. 2. After this enlargement 33 passes the springs they will snap back to their normal position and the fingers 2i thereon can then move into the lower recesses 36, which are also formed in the inner periphery E5 of the sub II).

The purpose of this sleeve i6 is to hold the valve 40 in open position. This valve is known as a back pressure or float valve because it is of the check valve type and is here shown as a flap valve which constitutes the valve member 4|, which is pivoted at 42 on the skirt 43, which projects downwardly from the pin member 9 on the sub Ill. The lower end of this skirt is formed with a curved seat 45 which is of the same configuration as the curved edge portion 46 of the valve member 4|. This valve is of curved configuration and is in the form of a cylindrical sector so that it will move backwardly into the enlarged chamber 6 in the sub 5 and occupy a minimum of space in order to permit passage of the core barrel 32, or other instrument. The spring member 41 normally urges the valve to closed position.

In operation, acore barrel or other instrument may be dropped downwardly through the drill stem and may engage the valve member 4| and move it to open position, if it is of small diameter, but usually there will be a diameter on the core barrel or instrument which will be of sufllcient size to engage the springs 20 and move the sleeve I6 to the position shown in Fig. 2. The instrument may or may not pass completely through the sleeve,depending upon its length and the type of instrument or tool which is inserted. In any event the sleeve l6 serves to hold the valve 40 in open position to protect it against becoming clogged with sand or sediment or to prevent its closing until the tool or instrument is removed or retrieved. This sleeve is also of advantage to prevent the valve from catching upon any enlargement of the tool or instrument which is passed therethrough. When the tool is removed or retrieved the spring 20 will be engaged by a portion of the tool or instrument, the latches will be released from the openings 36 and the sleeve will be raised to its inoperative position. The spring 41 will, of course, close the back pressure valve automatically so that there can be no reverse flow therethrough. Of course, if fluid is circulated downwardly through the drill stem the pressure thereof will open the back pressure valve. When the string of pipe is being floated into the well the back pressure valve will, of course, remain closed and will serve as a float valve to keep the string of pipe empty so that the flotation eflect of the empty pipe will reduce the weight being supported.

The invention broadly contemplates a float or back pressure valve to be incorporated in a string of pipe and which valve may be opened to permit the passage of a core barrel or other tool therethrough and to automatically close after the tool is removed.

What is claimed is:

1. A float valve assembly for drill pipe comprising a drill sub, a valve seat on the lower end thereof, a pivotal valve member on said sub, an adjoining sub, a chamber therein to receive said valve member in open position, a shoulder at the lower end of said chamber, and a sleeve movable longitudinally of said subs to a point above said valve seat so said valve may close and also movable to engage with said shoulder so as to hold said valve member in open position.

2. A float valve assembly for drill pipe compris ing a drill sub, a valve seat on the lower end thereof, a pivotal valve member on said sub, an adjoining sub, a chamber therein to receive said valve member in open position, a shoulder at the lower end of said chamber, a sleeve movable longitudinally of said subs to a point above said valve seat so said valve may close and also movable to engage with said shoulder so as to hold said valve member in open position, and latch means in said first sub to hold said sleeve in either up.- per or lower position.

3. A float valve assembly for drill pipe comprising a drill sub, a valve seat on the lower end thereof, a pivotal valve member on said sub, an adjoining sub, a chamber therein to receive said valve member in open position, a shoulder at the lower end of said chamber, a sleeve movable longitudinally of said subs to a point above said valve seat so said valve may close and to a, point below said seat to engage with said shoulder so as to hold said valve member in open position, and latch means in said first sub to hold said sleeve in either upper or lower position, said latch means being releasable by engagement or disengagement therewith of a tool movable through said subs.

4. A float valve for .a string of pipe in a well bore comprising a valve member curved to fit the inside cylindrical bore of the pipe when open, a curved seat therefor in said pipe, and means to hold said member in open position for the passage of a tool in the pipe and to cover said valve and protect it against wear.

5. A core drill and drill stem therefor, a core barrel to be inserted and withdrawn therefrom, an enlarged area on said core barrel, a back pressure valve in said drill stem, a sleeve also in said drill stem and movable to hold said valve in open position so that said core barrel may pass through said valve, and spring latch means on said sleeve to latch said sleeve in operative or inoperative position, said spring means being engageable by said enlargement so that said latch means will be released thereby as the enlargement passes and said sleeve will be moved by said core barrel.

6. A core drill and drill stem therefor, a core barrel to be inserted and withdrawn therefrom, an enlarged area on said core barrel, a back pressure valve in said drill stem, a sleeve also in said drill stem and movable to hold said valve in open position so that said core barrel may pass through said valve, and spring latch means on said sleeve to latch said sleeve in operative or inoperative position, said spring means being engageable by said enlargement so that said latch means will be released thereby as the enlargement passes and said sleeve will be moved by said core barrel, and stops to limit the movement of said sleeve in either direction.

MARCUS L. HACKER. 

